No evidence of shooting found after reports of ‘active shooter’ at US naval site

Reports of shots fired at a San Diego military hospital in southern California appear to be unfounded following an initial sweep of the building, according to authorities.

Navy spokesman Jon Nylander said there was no immediate evidence of a shooting or casualties after a witness reported hearing three shots in the basement of building 26 at the Naval Medical Centre San Diego at about 8am (local time).

“They did an initial sweep and they didn’t find anything, so they are doing a more thorough sweep,” Mr Nylander said.

“They have not located any evidence of a shooting having taken place.”

The Naval Medical Centre San Diego warned of the possible active shooter on Facebook and urged those to "run, hide or fight".

There were unconfirmed reports of shots being fired. (Supplied)

"**!ATTENTION!** An active shooter has just been been reported in building #26 at Naval Medical Center San Diego. All occupants are advised to run, hide or fight. All non-emergency response personnel are asked to stay away from the compound, located at 34800 Bob Wilson Drive, San Diego, CA 92134."

Local police, assisted by Navy dogs and California Highway Patrol officers, searched the building and lockdowns were put in place at nearby schools, however they have since been lifted.